Method of forming corrugated sheets



June 21, 1933. J. 1 BIXBY 1,916,120

METHOD OF FORMING CORRUGATED SHEETS Filed March 14, 1931 2 Sheets-Sheet, l

2G/'9.1. /a ./4 f fl f 7g wf /6 \F I -J Y J CII Patented June 27, 1933 UNITED STATES PATENT' OFFICE. j

JOHN L. BIXBY, F ARLINGTON, MASSACHUSETTS, ASSGNOR TO IKE-BOND COMPANY, .Y

INCORPORATED, 0F BOSTON, MASSACHUSETTS, .it CORPORATTON 0F MASSACHU- SETTS METHOD OF FORI/LING CORRUGATE) SHEETS Application filed March 14, 1931. Serial No. 522,686.

This invention relates to a novel and improved method of forming bonding sheets, and will be understood by reference to the following description of the method, wien L taken inl connection with the accompanying drawings illustrative thereof, while its scope will be pointed out more particularly in the appended claims.

Tn the drawings:

Fig. 1 is an edge elevation illustrating the appearance of the sheet in cross-section, following the lirst step of forming parallel corrugations having no overhanging surfaces, or undercut,

Fig. 2 is an edge elevation of the sheet as in Fig. 1, but on an enlarged scale, and illustrating by dotte-d lines the step of applying forces to the sheet to convert the corrugations to their final form; t

Fig. 3 is an edge elevation of the sheet in its final form, on the same sca-le as F ig. 1, illustrating by dotted lines the cross-sectional form shown in Fig. 1;

Fig. 1- is a cross-sectional view, illustrating portions of a pair of crimping or corrugating rolls, by which the first step in the method is performed; and

Fig. 5 is a cross-sectional view of portions of a pair of rolls, by which the second step in the method is performed.

Referring to the drawings, and to the method which is illustrated therein, and having reference at lirst to Fig. 3, which illustrates in full lines the sheet in its final form, there is shown a sheet of suitable material such as metal, usually steel, having two sets of oppositelydirected, dovetail forniatioiis or corrugations, constituted by two sets of flat portions and 11, whose faces are disposed in parallel planes A-A and B-B, and are connected by sets of portions 12 which are oblique tothe portions 10 and 11. The sheet, as viewed from one side, is characterized 'by alternating ridges and grooves of dovetail formation, two adjacent ridges having sloping sides which overhang the intervening groove,-that is to say, considering theI sides of each groove, they diverge from each other, from the plane A-A toward the plane To those skilled in the art of rolling sheet metal, it must be evident that it is impracticable to form with a single pair of rolls a sheet of dovetail formation such as that illustrated in Fig. 3, because of the overhang at the sides of each dovetail. Therefore, the

first step is to form the sheet to present on each side grooves alternating with hollow rid es which do not overhanor the Grooves..

More specifically, this step comprises forniing the sheet to present sets of parallel W shaped formations 13, alternating with sets of parallelV-shaped formations 1st. This step is conveniently accomplished by the user of a pair of rolls 15 (see Fig. l), which are fluted lengthwise to correspond with the described formation illustrated in Fig. l. The

.flat sheet is simply passed between the rolls,

and comes through-corrugated or crimped, with the formation imparted to it by the flutes on the rolls.

` The second step is to flatten the center apexes 16 of the W-shaped formation into a common plane B-B, and to flatten the apeXes 17 of the V-shaped formation into a common plane AuA, parallel ,with the plane B-B, and to turn the outer `sides of the Vil-shaped formation about parallel central axes C (see Fig. 2) thereby to form the two sets of oppositely-directed, dovetail forina- "i l12 are turned about the central axes C..

'This second step is accomplished conveniently by the use of a pair of forming rolls 18, longitudinally 'fluted to provide teeth 19 alternating with spaces 2O much wider than the teeth, the rolls being geared together and so placed with relation to each other that a tooth on onel roll enters'a space in the other, and occupies a position midway between two adjacent teeth of such other roll, u

as shown in Fig. 5. The sheet previously crimped or corrugated by the first step is.

passed between the rolls 18, in such away that the tooth of one roll presses upon one other roll then presses upon the next adjacent apeX17, andso on, the directions of the pressures being as previously described, shown by the arrows in Fig. 2. The com pleted sheet emerges from between the rolls apex 16, and the next adjacent tooth of the ill) in its final form, illustrated in full lines in Fig. 3.

Having thus described the method, what I claim and desire by Letters Patent to se- Clll'e 1S I 1. The herein-described method of forming a corrugated sheet, which comprises advancing a sheet while corrugating the same transversely of the direction of the advance and keeping the following portion of the sheet without substantial restraint to present on each side grooves alternating with hollow ridges which do not overhang the grooves, and subsequently manipulating the ridges to provide them with sides which over- -hang the grooves.

ridges with sides which loverhang the grooves.

3. The here1n-described method of forming a corrugated sheet, which comprises advancing a sheet while corrugating the same transversely ofthe direction of the advance and keeping the following portion of the sheet without substantial restraint to present on each side grooves alternating with hollow ridges which do not overhang the grooves, and subsequently advancing the sheet transversely of the ridges and pressing on the ridges in succession to press each ridge toward the opposite side of the sheet to provide said ridges with sides which overhang the grooves.

4. The herein-described method of forming a dove-tail corrugated sheet, which comprises advancing a sheet while corrugating the same transversely of the direction of the advance and keeping the following portion ofy the sheet without substantial restraint to present non-reentrant seri-ations, and advancing the sheet transversely of the serrations and deforming the serrations in succession to present undercut seri-ations by pressure exerted on selected apexes.

5. The herein-described method of forming a corrugated sheet, which comprises advancing a sheet while corrugating the same transversely of the direction of the advance and keeping the following portion of the sheet without substantial restraint to present a Zig-zag cross-section with ridges having sets of angularly disposed faces, and subsequently advancing the sheet transversely of said ridges and pressing on said ridges in succession to cause certain pairs of angularly disposed faces to occupy a common plane, to cause other pairs of angularly disposed faces to occupy another common plane parallel with the first plane, and to cause other pairs of angularly disposed faces to form overhanging sides of dove-tail grooves alternating with dovetail ridges.

6. The herein-described method of forming a dovetail corrugated sheet, which comprises advancing a sheet while corrugating the same tranrwersely of the direction of the advance and keeping the following portion of the sheet without substantial restraint to present a serrated cross-section, and advancing the sheet transversely of the seri-ations while pressing successively on non-sequent apexes alternately from opposite sides of the sheet to iiatten and evert the serrations corresponding to such apexes, and simultaneously to change the slope of a side intervening between said serrations.

7. The herein-described method of forming a dovetail corrugated sheet, which comprises advancing a sheet while corrugating the same transversely of the direction of the advance and keeping the following portion of the sheet without substantial restraint to present a serrated cross-section, and advancing the sheet transversely of the serrations while pressing successively on non-sequent apexes alternately from opposite sides of the sheet to flatten and cvert the serrations corresponding to such apexes and evert them substantially to the original plane of the other apexes.

8. The herein-described method of forming a dovetail corrugated sheet, which comprises advaneing asheet while corrugating the same transversely of the direction of the advance and keeping the following portion of the sheet without substantial rcstraint to present sets of parallel W-shaped formations alternating with sets of parallel V-shaped formations, and subsequently advancing the sheet transversely of the formations while successively exerting on the center apex of each W-shaped formation and on the apex of each V-shaped formation pressures in opposite directions, respectively, normal to said apexes, to flatten the center' apexes 0f the W-shaped format-ions into a commonplane, to flatten the apexes of the V-shaped formations into a common plane parallel with to turn the outer sides of each W-shaped formation about parallel, central axes, thereby to form two sets of oppositely-directed, dovetail formations, the dovetail fmniatiens of one set alternating with the dovetail for mations of the other set.

In testimony whereof, I have signed my name to this specification.

JOHN L. BIXBY.

and

the first-mentioned plane, and 

